Method and apparatus for data transmission in knitting machines

ABSTRACT

A method for transmitting data between an electronic needle selector system located on the carriage of a flat knitting machine and a stationary programmer unit, provides for transmission of the data optically and conversion of the data so transmitted into corresponding electrical signals using photoelectric transducers. The optical system includes pairs of light conducting rods which extend parallel to the direction of travel of the carriage and which serve to conduct light signals to and back from the needle selector system. The light conductor rods preferably include light transmissive side and end walls, the side walls of the first of rods of each pair of rods comprising a checkered pattern of alternate light transparent and light opaque sections the pitch of which is equal to the pitch of needles in the needle bed or beds of the machine.

United States Patent Hadam et al.

Inventors: Wilhelm I-Iadam, Reutlingen; Ernst Goller, Pfullingen, both of Germany H. Stoll & Company, Reutlingen, Germany Filed: Mar. 21, 1972 Appl. No.: 236,599

Assignee:

Foreign Application Priority Data Mar. 23, 1971 Germany";IILQQQQQ'P'2'1 i f'difs U.S. Cl. 66/75 R, 66/154 A Int. Cl. D04b 7/00, D04b 15/66 Field of Search 66/154 A, 75

References Cited UNITED STATES PATENTS 5/1962 MacQueen 66/154 A 5/l969 Sutton 66/l54 A NEEDLE SELECTOR SYSTEMS STATIONAR-Y PATTERNING 333 PROGRAM CARRIER 332 12 12 lZ5 l25 127 123 Jan. 8, 1974 57 ABSTRACT A method for transmitting data between an electronic needle selector system located on the carriage of a flat knitting machine and a stationary programmer unit, provides for transmission of the data optically and conversion of the data so transmitted into corresponding electrical signals using photo-electric transducers. The optical system includes pairs of light conducting rods which extend parallel to the direction of travel of the carriage and which serve to conduct light signals to and back from the needle selector system. The light conductor rods preferably include light transmissive side and end walls, the side walls of the first of rods of each pair of rods comprising a checkered pattern of alternate light transparent and light opaque sections the pitch of which is equal to the pitch of needles in the needle bed or beds of the machine.

14 Claims, 5 Drawing Figures .Z AIENTED 8 SHEET 2 UF 3 METHOD AND APPARATUS FOR DATA TRANSMISSION IN KNITTING MACHINES FIELD OF THE INVENTION This invention relates to a method of, and apparatus for, transmitting data relating to an electronic needle control system arranged between a fixed part and a moving part of a knitting machine. The invention is particularly applicable to a flat knitting machine wherein the needle control system is arranged between the machine body and the carriage.

BACKGROUND OF THE INVENTION In flat knitting machines of the type employing an electronic needle control system, the electronicallycontrolled needle selector systems are usually arranged on the moving carriage of the machine. Because of this, a problem exists of transmitting the data required for patterning control of the needle selector system on the moving carriage from a fixed patterning program carrier. The mounting of the patterning program carrier on the machine carriage is not feasible in practice because such an approach involves a substantial enlargement of the carriage with a consequent increase in the mass which has to be moved. In the case of a machine with long needle has to be moved. In the case of a machine with long needle beds difficulties are also involved in the transmission of electrical signals through a movable cable, since this approach'requires special cable tensioning and guiding arrangements. Moreover, the operation of the carriage of a machine employing this approach would be interferred with-by cables of this nature, and the load presented by the carriage would vary over the carriage stroke. Electrical signal transmission through free metal contact bars located on the body of the machine is also accompanied by disadvantages. These disadvantages result from contamination of the contact parts by exposure to lint or fluff and the need to provide relatively large safety gaps between the individual contact bars.

SUMMARY OF THE INVENTION The present invention avoids the aforementioned disadvantages through the provision of a method and api or a part rigidly connected to, and movable in the direction of travel of, such acarriage.

According to the present invention, the data is transmitted in one or both directions by optical means,and' is coverted atthe receiving end into electrical signals by means of photo-electric transducers or converters. In a preferred embodiment of the invention, at least one separate light conducting channel is associated with a needle selector system, or a group of like selec tor systems,-on the moving machine part. The optical data transmission between the fixed program carrier and the needle'selector systems on the moving machine part takes place in both directions through separate light conductingchannels. The approach provides a substantial increase in data transmission efficiency, and avoids need for signal separating arrangements.

In accordance with a presently preferred embodiment of the invention, a stationary light conducting rod extending parallel to the direction of carriage travel is provided for each needle selector system and for each direction of transmission. Each rod includes at least a one end and one side surface which is light transmissive, the surface opposite the light transmissive side surface being provided with inclined light-deflecting faces. Preferably, the light conducting rods are provided with a greater number of individually inclined light deflecting faces per unit length than there are needle tricks and intervening ribs per unit length in the needle bed of the machine, so to afford a proper and uniform light distribution over the light signaltransmissive sides of the rods. The light conducting rods which provide data transmission in one of the two directions of transmission preferably comprise, at the light signal-transmissive side surfaces thereof, a checkered pattern comprising light transparent and light opaque surface portions which alternate in thev longitudinal direction and are of a pitch which precisely corresponds to the pitch of the needles in the needle bed, or beds, of the machine.

The light energy of the light signals is preferably supplied by continuous light sources'which are arranged on the carriage of the flat knitting machine and/or at the side of the fixed patterning program carrier, the light from the source(s) being conducted through individual preferably flexible, light conductors located in the vicinity of the light signal-transmissive side faces and/orv to the light-transmissive ends of one of the light conducting rods of each pair of such rods. The flexible light conductors arranged on the machine carriage, in each case, provide for transmission of light into the zone of the checkered light signal-transmissive side surfaces of the first light conductor rod of one of each pair. Each of the first light conductor rods is provided at the light signal entry end thereof with a photocell connected to the input of an individual channel of the patterning program carrier. The output signals of the corresponding patterning program carrier channel control a device for producing light signals at the light signal-transmissive end of the second light conductor rod of the corresponding pair. The second light conductor rod of each pair of such rods has associated therewith a photoelectric transducer connected to the carriage, which transducer is electrically coupled to at least one of the needle selector systems.

vIn addition to the pair of light conducting rods associated with the individual needle selector systems, or groups of like needle selector systems, there are provided a plurality of supplementary lightconducting rods which extend parallel to one another and cooperate with further photoelectric transducers associated groupwise with the individual selector systems.

to a related selector system through a normal light conducting rod. Coincidence circuits ensure that the electrical control pulses are applied in timed succession to different control magnets belonging to the same selector system. The lightconducting rods with the optical receivers associated therewith and disposed thereover, are, in one embodiment, so masked over the full length as to prevent the incidence thereon of extraneous signals at the longitudinal output side of the rod. Alternately, the optical receivers are masked at the longitudinal output side over a length so as to prevent, by light defraction, extraneous light beams incident at the longitudinal outlet side of the rod from being transmitted to the optical receivers. In the latter case, the end of the rod opposite to the light emitter is not made refractive.

The arrangement provided at the side of the stationary patterning program carrier for producing light signals at the light signal entry end of the second light conducting rod of any one of the individual pairs of light conducting rods may comprise an electronic flash device which is controlled iri accordance with the output pulse of the associated patterning program carrier channel. The arrangement can, however, incorporate a continuous light source which has, in the zone of illumination thereof associated with the second light conducting rod of a pair of such rods, a Kerr cell which is electrically connected to the output of a patterning program carrier channel. In this alternative embodiment, a deflected beam from the Kerr cell passes to the entrance end of the second light conducting rod of an associated pair of such rods. The loss of light occurring with the use of Kerr cells may be compensated by a corresponding intensification of thecontinuous light source, and the increased expenditure of energy is compensated for by the lesser apparatus costs involved and the resulting unlimited length of life.

The provision of optical data transmission has the great advantages that it offers a complete guarantee against interference by other sources of radiation and that such an approach does not itself produce any interference with the needle control systems in adjacent machines.

Other features and advantages of the present invention will be set forth in or apparent from the detailed description of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more clearly understood and readily carried into practical effect, a specific arrangement thereof for optical data transmission in a flat knitting machine will now be described with reference to the accompanying, purely diagrammatic drawings, wherein,

FIG. 1 is a schematic diagram of an apparatus for optical data transmission in accordance with a presently preferred embodiment of the invention;

FIG. 2 is a plan view of a detail, drawn to an enlarged scale, of the apparatus of FIG. 1 showing one pair of light conducting rods;

FIG. 3 is a side view of the first light conducting rod of a pair of rods such as are shown in FIG. 2;

FIG. 4 is a side view of the second light conducting rod of the pair of rods of FIG. 2; and

FIG. 5 is a diagrammatic plan view of an alternative arrangement for producing a light signal in the second light conducting rod of a pair.

DESCRIPTION OF THE PREFERRED EMBODIMENT The data transmitting arrangement illustrated in FIG. 1 comprises a stationary patterning program carrier, denoted 10, in which is stored control data for nine needle selector systems 12 to 12 These systems are mounted on the carriage, denoted ll, of a flat knitting machine, in nine separate patterning program carrier channels. In FIG. 1 the inputs of the nine patterning program carrier channels are designated l3 l3,,,; and the outputs are designated 13 13 The channels advantageously comprise conventional shift registers the stored data of which is delivered cyclically. The details of construction of these channels form no part of the present invention and hence will not be described further.

Before going further it should be pointed out that for the sake of clarity and to avoid confusion, certain of the reference numerals appearing in the following description are not applied to the drawings for the reason that they are intended to indicate in a general way a collection of parts, components, locations or systems the individual ones of which are separately designed in the drawings by a running series of numerals bearing sue-- cessive indices. Thus, for example, the numerals 12 is sometimes used in the description to indicate a needle selector system, whereas in the drawings the nine needle selector systems are respectively designated 12, 12 Similarly, the number 13,, is used in the description to indicate an output, whereas in the drawings the nine outputs shown are respectively designated 13 13 in a like manner an input is indicated 13 whereas the nine inputs are respectively designated 13 -13 On the other hand, in each of FIGS. 1 and 2 the numerals l4 and 15 are applied to designate the two light conducting rods of a pair, these numerals being also used in the description, albeit that also in the description and in the drawings the first light conducting rods of the complete set of nine pairs are designated 14, 14 respectively while the second rods of the same pairs are respectively designated 15, 15 as noted below.

Separate optical transmission conductors are provided for the transmission of optical control impulses from the selected systems on the machine carriage 11 to the inputs 13 13 of the patterning program carrier channels, and also for the transmission of the control pulses which appear at the outputs 13 13 of the patterning program carrier channels to the individual selector systems on the said carriage. These transmission conductors basically comprise two kinds of light conductor rods, generally designated 14 and 15, which are arranged in pairs and are secured, parallel to the direction of travel of the carriage, to a stationary part of the flat knitting machine (not shown in detail) inthe effective zone of signal transmission members which are connected to the carriage and are hereinafter described in more detail.

Thus, referring to FIG. 1, a first light conducting rod 14 and a second-light conducting rod 15 are associated with the first selector system 12 whereas a first light conducting rod 14, and a second light conducting rod 15 are associated with the ninth selector system 12 The optical control pulse transmission from the carriage 11 to the inputs 13, 13 of the associated pattern program carrier channels 13 13, takes place through the first light conducting rods l4 14, of the nine pairs while transmission of the optical control signals from the outputs 13 13 of the patterning program carrier channels 13 13 to the associated selector systems 12 12 of the machine carriage respectively takes place through the second light conducting rods 15 15 of the pairs.

In the embodiment illustrated, three light conducting rods 16,, 16 and 16 (see FIG. 1), the purpose of which will be explained hereinafter, are additionally used as pulse emitters or sources.

As also can be seen in FIG. 1, a permanent light source 17 is mounted on the machine carriage 11. The light from source 17 is conducted through flexible glass fibre light conductors 18, 18 of a kind known per se, to the first light conducting rods 14 14 Each of the nine needle selector systems 12, 12 thus has associated therewith a relevant one of the light conductors 18, to 18 For reasons explained hereinbelow, each of the ends of light conductors 18, to 18 (one of which, denoted 18 is shown in FIG. 2) is directed to the associated one of the needle selector systems 12, 12 and is arranged over the appropriate one of the first light conducting rods 14, 14,, associated with that particular needle selector system.

Referring to FIG. 2, there is shown a part of a needle bed 19 of a flat knitting machine with needle tricks 20 therein and intervening ribs 21 thereon. Also shown in FIG. 2 is a broken away portion of the carriage 11 and portions of the first pair of light rods, specifically, the first light conducting rod 14, and the second light conducting rod 15,. The light conducting rods 14 and are both of the same dimensions and both of rectangular cross section. In contrast to the second light conducting rod 15, the first light conducting rod 14 of each pair has a light signal transmissive side surface 14,, (see FIG. 3) which, in contrast to the corresponding surface 15, of rod 15 (see FIG. 4) is provided with a checkered pattern made up of an alternate sequence of light transparent surface portions 22 and light opaque surface portions 23. As shown in FIG. 2, the transparent surface portions 22 of the first light conducting rod 14, are of the same pitch as the needle tricks in the needle bed 19.

As can be seen in FIGS. 3 and 4, the two types of light conducting rods 14 and 15 are provided at the sides thereof opposite the light signal transmissive side surfaces 14, and 15,, with a large number of inclined faces 24. These side walls of rods 14 and 15, which are respectively denoted 14,, and 15,,, are of sawtooth or zigzag form in cross section and present a highly reflective surface. Preferably, the faces 14,, and 15,, are graduated or divided much more finely than the pitch of the needles in the needle bed 19 and hence-more finely than the corresponding checkered effect at the light emitting side surfaces 14,, and 15,. These faces 14,, and 15,, are, moreover bevelled to such a degree that the light beams incident thereon, formed by the light passing side surfaces of the first and second light conducting rods 14 and 15 of each pair, are deflected into approximately the longitudinal direction of these rods, and vice versa (see beam 26 of FIG. 3 and beam 28 of FIG. 4). In addition to their light-transmissive longitudinal sides 14, and 15,, the light conducting rods 14 have a light signal exit 14 and light conducting rods 15 have a light signal entrance 15 Light can enter and leave the light conducting rods 14 and 15 only through these entrances and exits. All the other surface parts of these rods are light opaque and provided with mirror surfaces which reflect incident light beams which have not already been reflected by internal reflection.

As mentioned above, the flexible light conductors 18, to 18,, which are connected to the machine carriage light source 17 on the carriage 11, terminate in ends such as 18,,(See FIG. 3) over the checkered light signal-transmissive sides 14,, of the first light conducting rods 14, to 14,, of the pairs. A photocell 25 is secured to the light signal-transmissive end 14 of rod 14, photocell 25 transforming the light pulse transmitted through the light conducting rod 14 into an electrical pulse. The electrical pulse so produced is transmitted through an associated one of the inputs 13,, 13 of the corresponding channel of the patterning program carrier 10 and, in this specific instance, through input 13,, as shown in FIG. 3. A light pulse or beam, depicted by an angular stream line 26 carrying directional arrows, enters the light conducting rod 14 whenever the end 18,, of the associated light conductor 18 of the carriage is located above a transparent surface portion 22 of the light signal-transmissive longitudinal side 14,, of the light conducting rod 14.

The second light conducting rod 15, which is best seen in FIGS. 2 and 4, has an uncheckered lighttransmissive longitudinal side 15,, and a photoelectric converter, in the form of a photocell 27 secured to the machine carriage 11, isarranged thereover. Photocell 27 receives a light pulse or beam which is produced by a flashlight tube 29 and depicted by an angular stream line 28. The tube 29 is arranged at the light signaltransmissive end 15, of the light conducting rod 15 and is controlled by the output signal from the associated channel 13, of the patterning program carrier 10. The light pulse received is converted by the photocell 27 into an electrical control pulse which is conducted through one of lines 30, 30,, (See also FIG. 1), and, in this instance, through line 30, as shown in FIG. 4, to the associated needle selector system 12, of systems When the carriage 11 moves in one or the other direction, the entrance of the permanent light emergent from the ends 18 of the light conductors l8 18,, is periodically interrupted by the opaque surface portions 23 of the checkered surface of rod 14, and at a frequency which is exactly equal to the speed of travel of the carriage multiplied by the pitch of the needle tricks 20 in the needle bed 19. This produces light pulses in the first light conducting rods 14'which are transmitted in the form of electrical pulses from the photocells 25 to the inputs 13 of the associated patterning program carrier channels 13 and which periodically scan'instructions from the storage content of these channels. Each patterning program carrier channel, which, as mentioned above, is preferably in the form of a shift register memory, applies the signals stored therein to its output 13,, at the scanning frequency. These signals comprise so-called L-si'gnals and O-signals and the L- 11 and arranged to transmit light from the permanent signals are converted by the relevant flash tube 29 into a light pulse which is projected into the associated second light conducting rod 15. This light pulse is in turn converted by the associated photocell 27 into an electrical control pulse for the associated one of the needle selector systems 12, 12 Thus, there is a light emitter or source and a light converter or transducer associated with each of the needle selector systems 12, 12,, arranged on the carriage 11, the said light emitter and the light converter being operated through separate light paths, namely the light conducting rods 14 and 15 of the relevant pair.

Each of the needle selector systems 12, 12,, may comprise a plurality of individually operable control magnets for the setting of cam parts or for direct needle selection in accordance with conventional selector systems. In this regard, it is assumed that in the embodiment illustrated there are three such control magnets per selector system 12, in which instance the control signals passing through the conductors are branched into three separate operating magnet control pulses in the selector systems. This is achieved by means of the additional pulse emitter light conducting rods 16, 16;, mentioned above. In the arrangement illustrated in FIG. 1, these three pulse emitter-light conducting rods are continuously supplied through the entrance ends thereof with light from a permanent light source 31. Rods 16, 16 include light signal-transmissive sides, denoted 32, which are provided with opaque masking portions 33. The masking portions 33 are relatively staggered as between the three light conducting rods 16, 16 and the pitch of the opaque patterning on these rods is three times that of the checkered pattern provided on the first-mentioned light conducting rods 14. Three photoelectric converters or tranducers (not shown in detail) co-operate with each of the light conducting rods 16, 16 for each needle selector system and in alignmebt with these selector systems 12, the said converters being connected through electrical leads 33, 33,, to the individual needle selector systems. The pulses produced by these convertes are staggered in phase in the leads 33, -33 in dependence on the relative offsetting of the masked portions 32 on the impulse emitter light conducting rods 16, 16 and are applied to one of the inputs of three separate coincidence circuits, e.g., AND-gates, (which have not been shown in the drawing), while the control signal on lead 30 is applied to the second of the inputs of these circuits. The outputs of the three coincidence circuits are in each case connected with one of the three control magnets of the relevant needle selector system 12. Thus, there is a cyclic sequence of periodic signals applied to the leads 33, 33 the overall frequency of these signals being equal to the speed of travel of the carriage 1 1 times the pitch of the needle tricks 20 in the needle bed 19.

Referring to FIG. 5, a modified embodiment is shown of the stationary light emitting arrangement controlled by the patterning program carrier. In this modified arrangement, instead of using a flash tube 29 as described above in connection with FIG. 4, a Kerr cell 34 is associated with the second light conducting rod 15 of each pair. The Kerr cells 34 (only one of which is shown in FIG. 5) are each electrically connected, through an amplifier (not shown), to the output 13,, of an associated channel of the patterning program carrier 10.

.Each of the Kerr cells 34 is exposed to a beam from a permanent light source 36 through lenses such as 37. So long as there is no L-output signal from the patteming program carrier channel applied to the input of the Kerr cell 34, the light incident on cell 34 passes rectilinearly through this cell as a so-called normal or steady light beam, denoted 38. The Kerr cell 34 is so positioned such that a normal beam 38 therefrom cannot pass to the signal-transmissive end 15 of the associated light conducting rod 15 and hence beam 38 does not cause a signal to be transmitted through leads 30 to needle selector systems 12. If an L-signal is applied to the Kerr cell 34 a part of the incident light is deflected to form an extraordinary light beam 39 which is transmitted to the light signal-passing end 15 of the associated light conducting rod 15.

The carriage of a flat knitting machine has certain needle selector systems duplicated, one ofv these systems working in one direction of travel of the carriage and the other in the other direction. Such like selector systems, since they are never used simultaneously, may in each case be connected to the pattern program carrier 10 through a pair of light conducting rods 14, 15. Co-ordination of the received control pulse with the needle selector system to be operated at a given time can be achieved through the agency of switches or the like on the carriage which are operable in dependence on the direction of travel of the latter.

Although the invention has been described relative to specific exemplary embodiments thereof, it will be understood by those skilled in the art that variations and modifications in these embodiments can be effected without departing from the scope and spirit of the invention.

We claim:

1. In a knitting system comprising a flat knitting machine having a movable machine carriage including at least one electronic needle selector system including at least one control magnetlocated on said carriage and a fixed patterning program carrier for controlling the operation of the electronic needle control system, the improvement wherein optical means for transmitting data related to the operation of the electronic needle control system between the control system and the patterning program carrier including at least first and second stationary light conductors disposed parallel to the direction of travel of the carriage for transmitting said data to said control system from said carrier and to said carrier from said control system, respectively; at least one end and one side of each said light conducting rod being light transmissive, the side of said rod opposite the transmissive side being light reflective so that light incident thereon is reflected.

2. A system as claimed in claim 1, wherein the light reflecting side of each light conducting rod includes a plurality of light reflecting, inclined surfaces, the number of which per unit length of the rod, is greater than the number of needle tricks and intervening ribs for the same unit of length in the needle bed of the machine.

3. A system as claimed in claim 2, wherein said system includes a plurality of pairs of said light conducting rods and said first light conductor rod of each of said plurality of pairs of said rods includes at the light transmissive side surface thereof a checkered pattern of surface portions which are alternately light transmissive and light opaque successively along the longitudinal axis of the rod, the pitch of a subdivision of this pattern being equal to the pitch of the needles in the needle bed.

4. A system as claimed in claim 2, wherein a continuous light source is disposed on the carriage of the knitting machine, the light from said source being conducted through individual flexible light conductors and the light emerging from each of said flexible light conductors being directed into the zone'of a light transmissive portion of one of the light conductor rods of each pair of said rods.

5. A system as claimed in claim 4, wherein a further continuous light source is disposed adjacent the fixed program carrier, the light from said further source being conducted through further individual flexible light conductors and the light emerging from each of said further flexible light conductors being directed into the zone of a light transmissive portion of the other of said light conductors of each said pair of said rods.

6. A system as claimed in claim 5, wherein the flexible light conductors associated with light source on the machine carriage transmit light from the continuous light source into the zone of the checkered light transmissive side surface of the first light conductor rod of each pairof said rods, said first light conductor rod including a photocell at the light signal entry end thereof connected to the input of an individual channel of the patterning program carrier, theoutput signal of the corresponding patterning program carrier channel controlling a means for producing light signals at the light transmissive end of the second light conductor rod of the said pair.

7. A system as claimed in claim 6, further comprising a photo-electric transducer associated with the second light conductor rod of each pair of said rods, each said transducer being connected to the carriage and being electrically coupled to at least one of the needle selector systems.

8. A system as claimed in claim 7, further comprising pulse generators in the form of a plurality of supplementary light conducting rods which extend parallel to one another and co-operate with further photo-electric transducers associated group-wise with the individual needle selector systems, said supplementary rods including one longitudinal signal comprising staggered light transmissive and light opaque surfaces, the subdivisions in which are a whole number multiple of the individual subdivisions in the said checkered pattern sides of the first mentioned light conducting rods.

9. A system as claimed in claim 8, further comprising means for connecting the photo-electric transducers co-operating with the pulse generator light conducting rods and the photo-electric transducers associated with the pairs of light conducting rods, through coincidence circuits to a plurality of control magnets in each of the associated needle selector systems.

10. A system as claimed in claim 6, wherein said means for producing light signals at the light signal entry end of the second light conducting rod of each pair of said rods comprises an electronic flash tube, which is operated independently of the output pulses of the associated patterning program carrier channel.

11. A system as claimed in claim 6, wherein the means for producing light signals at the light signal entry end of the second light conducting rod of each pair of said rods comprises a continuous light source, and a Kerr cell associated with each said second light conducting rod and illuminated by said continuous source, each cell being electrically connected to the output of a patterning program carrier channel, and deflected beams from said cells passing to the entry end of the second light conducting rod of an associated pair of such rods.

12. A system as claimed in claim 1, wherein each patterning program carrier channel comprises a shift register which is associated with a relevant needle selector system.

13. A system as claimed in claim 8, wherein the pairs of light conducting rods and the supplementary light conducting rods follow the racking movements of the needle bed.

14. A method of transmitting data related to the operation of an electronic needle control system between stationary and moving parts of a knitting machine comprising converting electrical data pulses into light pulses at the stationary part of the knitting machine, transmitting said light pulses through a directed optical path to the moving part of the knitting machine, and converting the light pulses into electrical data pulses at the moving part of the knitting machine; and producing a constant light signal at the moving part, dividing said constant light signal into further light pulses as a function of the movement of the moving part of the knitting machine, transmitting said further light pulses through a directed optical path to the stationary part of the knitting machine, and converting said further light pulses into electrical control signals at the stationary part of the knitting machine. 

1. In a knitting system comprising a flat knitting machine having a movable machine carriage including at least one electronic needle selector system including at least one control magnet located on said carriage and a fixed patterning program carrier for controlling the operation of the electronic needle control system, the improvement wherein optical means for transmitting data related to the operation of the electronic needle control system between the control system and the patterning program carrier including at least first and second stationary light conductors disposed parallel to the direction of travel of the carriage for transmitting said data to said control system from said carrier and to said carrier from said control system, respectively; at least one end and one side of each said light conducting rod being light transmissive, the side of said rod opposite the transmissive side being light reflective so that light incident thereon is reflected.
 2. A system as claimed in claim 1, wherein the light reflecting side of each light conducting rod includes a plurality of light reflecting, inclined surfaces, the number of which per unit length of the rod, is greater than the number of needle tricks and intervening ribs for the same unit of length in the needle bed of the machine.
 3. A system as claimed in claim 2, wherein said system includes a plurality of pairs of said light conducting rods and said first light conductor rod of each of said plurality of pairs of said rods includes at the light transmissive side surface thereof a checkered pattern of surface portions which are alternately light transmissive and light opaque successively along the longitudinal axis of the rod, the pitch of a subdivision of this pattern being equal to the pitch of the needles in the needle bed.
 4. A system as claimed in claim 2, wherein a continuous light source is disposed on the carriage of the knitting machine, the light from said source being conducted through individual flexible light conductors and the light emerging from each of said flexible light conductors being directed into the zone of a light transmissive portion of one of the light conductor rods of each pair of said rods.
 5. A system as claimed in claim 4, wherein a further continuous light source is disposed adjacent the fixed program carrier, the light from said further source being conducted through further individual flexible light conductors and the light emerging from each of said further flexible light conductors being directed into the zone of a light transmissive portion of the other of said light conductors of each said pair of said rods.
 6. A system as claimed in claim 5, wherein the flexible light conductors associated with light source on the machine carriage transmit light from the continuous light source into the zone of the checkered light transmissive side surface of the first light conductor rod of each pair of said rods, said first light conductor rod including a photocell at the light signal entry end thereof connected to the input of an individual channel of the patterning program carrier, the output signal of the corresponding patterning program carrier channel controlling a means for producing light signals at the light transmissive end of the second light conductor rod of the said pair.
 7. A system as claimed in claim 6, further comprising a photo-electric transducer associated with the second light conductor rod of each pair of said rods, each said transducer being connected to the carriage and being electrically coupled to at least one of the needle selector systems.
 8. A system as claimed in claim 7, further comprising pulse generators in the form of a plurality of supplementary light conducting rods which extend parallel to one another and co-operate with further photo-electric transducers associated group-wise with the individual needle selector systems, said supplementary rods including one longitudinal signal comprising staggered light transmissive and light opaque surfaces, the subdivisions in which are a whole number multiple of the individuAl subdivisions in the said checkered pattern sides of the first mentioned light conducting rods.
 9. A system as claimed in claim 8, further comprising means for connecting the photo-electric transducers co-operating with the pulse generator light conducting rods and the photo-electric transducers associated with the pairs of light conducting rods, through coincidence circuits to a plurality of control magnets in each of the associated needle selector systems.
 10. A system as claimed in claim 6, wherein said means for producing light signals at the light signal entry end of the second light conducting rod of each pair of said rods comprises an electronic flash tube, which is operated independently of the output pulses of the associated patterning program carrier channel.
 11. A system as claimed in claim 6, wherein the means for producing light signals at the light signal entry end of the second light conducting rod of each pair of said rods comprises a continuous light source, and a Kerr cell associated with each said second light conducting rod and illuminated by said continuous source, each cell being electrically connected to the output of a patterning program carrier channel, and deflected beams from said cells passing to the entry end of the second light conducting rod of an associated pair of such rods.
 12. A system as claimed in claim 1, wherein each patterning program carrier channel comprises a shift register which is associated with a relevant needle selector system.
 13. A system as claimed in claim 8, wherein the pairs of light conducting rods and the supplementary light conducting rods follow the racking movements of the needle bed.
 14. A method of transmitting data related to the operation of an electronic needle control system between stationary and moving parts of a knitting machine comprising converting electrical data pulses into light pulses at the stationary part of the knitting machine, transmitting said light pulses through a directed optical path to the moving part of the knitting machine, and converting the light pulses into electrical data pulses at the moving part of the knitting machine; and producing a constant light signal at the moving part, dividing said constant light signal into further light pulses as a function of the movement of the moving part of the knitting machine, transmitting said further light pulses through a directed optical path to the stationary part of the knitting machine, and converting said further light pulses into electrical control signals at the stationary part of the knitting machine. 